/Engine/Plugins/Experimental/GameplayBehaviors/Source/GameplayBehaviorsModule/Public/BlackboardKeyType_GameplayTag.h
Check if key has stored value, works directly on provided memory/properties
virtual bool IsEmpty ( const [UBlackboardComponent](API\Runtime\AIModule\BehaviorTree\UBlackboardComponent) & OwnerComp, const uint8 * MemoryBlock ) const